How it All Began
It all started in 1998 when John Wick and Peggy Rathmann bought a 540-acre California ranch. Unfortunitly, the ranch’s soil had seen much better days. Years of overgrazing hurt the ranch’s land, which made it difficult for the ranchers to grow grass.
To help remedy the problem, Wick called Jeffrey Creque, a rangeland ecology expert. After discussing the problem, it was decided that the soil would improve if the ranchers planted grass. An obvious conclusion, but that simple thought gave the two a brilliant idea. “They knew that in addition to enriching the soil, healthy grass, through photosynthesis, could remove carbon from the atmosphere,” Mother Jones reports. “So was there a way, they wondered, to grow more grass on Wick’s land and slow global warming at the same time?”
“Carbon that is absorbed by grass can be stored for hundreds of years in the grass’ roots and surrounding soil—a much better spot for it than in the air, where it warms the planet in the form of carbon dioxide. Carbon-enriched soil, in turn, feeds grass so it can grow taller and suck down even more carbon.”
This process happens on a pretty big scale in rangelands–almost a third of the world’s carbon is stored in grass and soil. But processes, such as tilling and overgrazing, allow carbon to escape while causing topsoil erosion. This makes grass difficult to grow.
And when rangelands are populated by livestock, the problem can get worse because, well, cow poop. “Manure releases methane and nitrous oxide gases into the atmosphere,” Mother Jones reports. “In fact, livestock are responsible for nearly one-fifth of the globe’s overall greenhouse gas emissions.”
So, to help the ranchers’ grass along, Creque decided to add compost to the mix. Compost is filled with carbon-rich organic waste–basically, yard clippings, food scraps, and manure can help eat carbon when spread across soil–or rangelands, in this case, that “digest the carbon and deposit it into the soil before it could escape into the air. The rich soil, now full of carbon and microbes, would feed the grass—which would absorb yet more carbon.”
Wick decided to give the idea a shot and got the help of Whendee Silver, an environmental scientist at the University of California-Berkeley. They secured grants to run a large-scale compost experiment. “For about $300 plus the cost of shipping, Wick bought 31 tons of compost from a facility that collects it from homes in the Sacramento Valley. Wick and Silver then spread it out on Wick’s ranch,” Mother Jones reports. “The results exceeded expectations. As the grass grew, tests suggested it absorbed an average of 0.4 tons of carbon per acre a year—and that, all told, the land was capturing at least 25 percent more carbon. Silver has since tried the concept in other climates—it works even in the hot, dry Sierra foothills.”
What Does This Mean?
The big story here is that if “compost were added to 5 percent of California’s rangelands, Silver calculates, those 3.2 million acres could eliminate 7.6 million tons of carbon emissions over a three-year period, equal to taking about 2 million cars off the roads annually.”
This is a big idea. And if compost can help keep soil healthy, grow more food, and slow climate change, why aren’t we doing it on a larger scale?